Process and apparatus for the filling, transportation and dispensing of hazardous fluids



06L 1964 l. A. COHEN ETAL 3,151,467

PROCESS AND APPARATUS FOR THE FILLING, TRANSPORTATION AND DISPENSING 0F HAZARDOUS FLUIDS 2 Sheets-Sheet 1 Filed Dec. 4, 1961 INVENTORS A. COHEN RTLEY C. DELLINGER IN S v v-ltLiiin s JO y j M fa/4. M.

A T TORNEV Oct. 6, 1964 A. COHEN ETAL 5 PROCESS AND APPARATUS FOR THE FILLING. TRANSPORTATION AND DISPENSING 0F HAZARDOUS FLUIDS 2 Sheets-Sheet 2 Filed Dec. 4, 1961 INVENTORS ATTORNEY United States Patent PROCESS AND APPARATUS FOR THE FELLHNG,

TRANSPORTATION AND EISPENSING 0F HAZ- ARDOUS FLUIDS Irving A. Cohen, Williams'tille, Hartley C. Deliinger, Tonawanda, Martin L. Kashohm, Wiliiamsville, and John N. Williams, Tonawanda, N.Y., assiguors to Union (Jarhitle Corporation, a corporation of New York Filed Dec. 4, 1961, Ser. No. 156,877 6 Claims. (Cl. 62-48) This invention relates to a process of and apparatus for the filling, transportation and dispensing of hazardous fluids, and more particularly to apparatus which provides a safe and economical means for the storage and transportation of liquid or solid acetylene and process for filling and dispensing the contents of the apparatus in a safe and eificient manner.

The commercial process currently in use for storing and shipping acetylene is one in which the acetylene is stabilized by dissolving it in a solvent such as acetone. The dissolved acetylene container comprises a metal vessel (cylinder) filled with a porous solid material, usually called a filler, and a quantity of acetone. Acetylene gas is then dissolved in the acetone under pressure. The solvent and filler are required to stabilize the acetylene since acetylene under pressure is sensitive to the inititaion of exothermic decomposition. This system has the disadvantage of discharging acetylene contaminated with minor amounts of acetone.

The dissolved acetylene cylinder is a costly way of storing and shipping this gas because the acetylene itself makes up only a small fraction of the total weight of the package. For the dissolved acetylene cylinders in current commercial use the acetylene represents only about 10 percent of the total weight.

It is the main objective of this invention to provide a safe and efiicient method for the storage and transport of acetylene which is not subject to the disadvantages of the present commercial process as pointed out above.

It is a further objective of the present invention to provide an acetylene converter for the safe and economical transportation, storage and dispensing of acetylene.

It is a still further objective of the present invention to provide a safe and economical process for the filling and dispensing of acetylene from the acetylene converter herein discussed and illustrated.

As used herein the term acetylene converter refers to a storage vessel which converts solid or liquid acetylene into gaseous acetylene as contrasted with a conventional acetylene cylinder which dispenses its contents by a desorption process.

In the drawings FIG. 1 is a view in section of acetylene converter according to the instant invention and including schematic flow diagram of exemplary heating and cooling systems used in charging and dispensing acetylene to and from the converter;

FIG. 2a is an enlarged fragmentary view showing a heat transfer coil embedded in a porous medium showing a plastic coating on the coil prior to its removal to provide controlled acetylene gas passageways;

FIG. 2b is an enlarged fragmentary view of a heat transfer coil embedded in a porous medium illustrating the gas passageway adjacent thereto resulting after the removal of the plastic coating illustrated in FIG. 2a;

FIG. 3 is an enlarged fragmentary view of a heat transfer coil embedded in a porous medium illustrating the association of the gas passageways of FIG. 2b with the gas passageways extending the length of the heat transfer coils; and

FIG. 4 is a fragmentary view in section of the acetyl- 3,151,457 Patented Get. 5, 1964 ene inlet-discharge connection illustrating a flash arrester means housed therein.

According to the present invention, liquid or solid acetylene is rendered inert and safe for storage or transport by introducing the acetylene into the pores of a solid stabilizing medium enclosed in the inner container of a storage and transport system. The present invention also provides efiicient and safe methods for introducing the acetylene into the porous stabilizing medium and withdrawing the acetylene from the stabilizing medium. The porous medium of the storage and transport system desensitizes the acetylene by preventing the initiation of decomposition under all expected conditions of service. In addition to the stabilizing influence of the porous filler, flash-arrester means are provided at critical locations to protect the desensitized acetylene from severe shock in the event a flash is propagated from without the inner vessel, for example, in the consuming line which conveys gaseous acetylene to the user.

The apparatus of this invention includes a closeable vessel containing a porous stabilizer in Whose pores or interstices liquid or solid acetylene can be stored and which also contains an intricate system of passageways adjacent to the heat transfer surfaces embedded in the porous stabilizer. This latter feature provides a path for acetylene during charging and discharging of the vessel. These passageways are preferably provided by removing a suitable plastic which has been previously coated on and around the embedded heat transfer surfaces within the porous medium.

The handling process of this invention comprises introducing gaseous acetylene into a porous stabilizing medium while the medium is preferably cooled by means of embedded heat transfer coils, and condensing the gas within the porous medium. Acetylene may then be vaporized and discharged as a gas by passing a warm fluid through the same embedded heat transfer coils. In this fashion gaseous acetylene is both introduced and withdrawn from the container eliminating the necessity and danger for handling liquid or solid acetylene in an unstabilized form.

The porous, solid stabilizers which may be used with this invention prevents the initiation of decomposition of solid or liquid acetylene by providing energy-absorbing material close to each part of the acetylene lying within the pores of the stabilizer.

To be useful as a desensitizer for solid or liquid acet ylene the porous, solid material should be chemically inert toward acetylene and toward the materials of the vessel within which the material is contained, it should not be soluble in liquid acetylene and it should have a high heat capacity for absorbing heat in the temperature range from about 82 C., the melting point of acetylene, to about 13 00 C., the critical temperature for propagation of acetylene decomposition flame.

Not only should the composition of the porous stabilizer be such that its potential stabilizing eifect is great, but also its physical form should be such that its potential stabilizing eifect is largely realized. The pore size is important for two reasons. First, the pores must be small enough so that the liquid-acetylene will not, drain from the porous stabilizer by gravity, but rather will be held within the central region of the package by capillary action. Second, the pores must be small enough so that the acetylene within them is eflectively stabilized against decomposition. The mechanism by which condensed acetylene is desensitized by a solid material depends, in part at least, on the rapid absorption by the porous medium of energy from sources external or internal of the storage mass. Energy from an external source is absorbed in part directly by the porous medium, and the local intensity of the energy will not normally reach the level needed for ignition. If incipient local decomposition should occur, the porous medium will absorb heat generated internally fast enough to quench the reaction and prevent Wide-spread decomposition of acetylene. It has been found that for satisfactory stability in the system of this invention the pores should have a maximum crosssectional dimension between about 0.005 to 50 microns. The pores'or interstices should be inter-connected and at least some of them should have a diameter approaching the large end of this range in order that charging and discharging will not be diiiicult. The particles that comprise the porous stabilizer must be of such shape and size as to provide enough pores of the desired size to accommodate the liquid acetylene.

Examples ofmaterials which, when in the proper state of subdivision to provide pores having a maximum crosssectional dimension of about 0.005 to 50 microns, are useful as stabilizing media for solid or liquid acetylene are alumina trihydrate and calcium carbonate. The pre ferred porous stabilizer, however, is a monolithic calcium silicate filler prepared in accordance with the teachings of U.S.P. 2,883,040. Hereinafter stabilizing medium will be referred to as porous silica-lime filler. In addition to the filler set forth in the aforementioned patent, the process for treating or curing the filler is also preferred.

Referring to the drawings and particularly to FIG. 1 there is illustrated the acetylene converter of the instant invention and its essential components comprising an inner vessel and an outer shell 12. Between the inner vessel 10 and outer shell 12 is a suitable thermal insulating material 14. Insulating material 14 is preferably a heat stable powder insulation which is maintained under vacuum or preferably at a slight positive pressure between shell 12 and vessel 10. Suitable pressurizing gases are dry nitrogen and argon. Other gases may, however, be employed, the only criteria being that the particular pressurizing gas not condense against the liquid or solid acetylene-chilled vessel 10. Containedthroughout vessel 10'is a porous silica-lime filler material 16 having between 86 to 93% porosity which has been prepared and processed according to the teachings of U.S.P. 2,883,040 as previously mentioned. Embedded within the silica-lime filler 16 are a plurality of heat transfer coils 18 extending the length of the converter. Heat transfer coils 18 are connected to manifolds 20 and 21 which receive or discharge a suitable heat transfer fluid to cool or to warm the porous silica-lime filler 16. Interwoven down the turns of heat transfer coils 18 is a plastic material bonded to a supporting material 22 such as common steel window screen, which supports the plastic material thereby permitting the plastic material to be wound around the entire length of heat transfer coils 18. A plastic coating is also applied to the individual turns of heat exchange coils 18 but an additional supporting material is not necessary. The plastic material applied to the individual turns of heat transfer coils 18 and the plastic bonded screen 22 is preferably provided by an acetone or trichloroethylene solution of poly-methylmethacrylate. The plastic coating and plastic bonded screen material are applied and installed respectively prior to the curing of porous sand-lime filler 16. In the latter stages of curing the'porous sand-lime filler as taught in U.S.P. 2,883,040, the temperature ofthe curing process is raised sufficiently to gasify the plastic material and completely remove same from within the converter. Once this has been accomplished the converter will thus have been equipped with an intricate series of passageways for the receiving or discharging of acetylene from the pores of the sandlime filler. In securing the intricate series of passageways in the aforementioned manner one important consideration is the velocity of acetylene flow from the filler to the passageways. If the velocity in a heavily loaded filler is too great, liquid acetylene may be drawn into the gas stream and carried outside the filler mass. It is imperafive that such entrainment be avoided if the objectives of this invention are to be achieved. For maximum safety, it is mandatory that all liquid acetylene be confined within the porous silica-lime filler at all times. Another important consideration in passageway design is heat transfer between tubes and filler. The flow spacings formed when the plastic material is evaporated constitutes a heat transfer resistance. We have found that the spacing between tube and filler should be between about /2 mil to about 3.0 mils. Below /2 mil clearance the velocity of acetylene gas being withdrawn from the converter becomes very high; this increases the hazard of entraining liquefied acetylene in the gas stream. A further restriction on spacings below /2 mil resides in the difficulty of coating heat transfer coils 18 to achieve such a small spacing. Above a 3 mil passage clearance the resistance to heat transfer increases markedly thereby prolonging both the charging and discharging operations.

Operating in conjunction with the spacing between heat transfer coils l3 and porous silica-lime filler 16 is the amount of heat transfer area which should be made available for efiicient use of the acetylene converter herein presented. For satisfactory economy and performance we have found that at least 1.0 ft. of heat transfer area should be made available within inner vessel 10 for each cubic foot of porous silica-lime filler 16 contained therein. If this minimum value of 1.0 ft. of heat transfer area per cubic foot of porous filler is not adhered to, unattractively-low filling and withdrawal rates are experienced. Preferably at least 1.5 ft. heat transfer area per cu. ft. filler is provided.

In addition to the safety feature of the porous silicalime filler 16, additional flash arrester means are provided. One such flash arrester means is located in the inlet-discharge connections 24. Details of the construction of this flash arresting means are illustrated in FIG. 4. Still additional flash arrester means is shown generally at 28 adjacent the converter connection to a consuming system. Flash arrester means 23 is essentially a bed of suitable packing or a bundle of small tubes packed inside a cylinder or chamber. This packed chamber assembly divides the flow channel of the chamber into a large number of small passages whose cross-sectional widths are inch or less. The reason for this division of the flow channel is that a flash under usual conditions of operation will not propagate through a channel of such small dimension owing to the large surface area in contact with the gas for conducting heat away from the combustion zone. Between connections 24 and flash arrester means 28 a tube system 30 contains a packing consisting of many smaller tubes aligned parallel with the flow to stabilize the acetylene flowing therethrough. The external flow system of the acetylene converter of this invention, therefore, is essentially a continuous fiash arrester, i.e., the inlet or discharge connections are provided with a flash arresting means, and the conduit 30 connecting all inlet-discharge connections with flash arresting means 28 has an internal flash arrester means therein to stabilize acetylene llow. Finally flash arresting means 28 is proportion of a turn of heat transfer coil 18. FIG. 2a illustrates the heat transfer coil before the plastic coating has been removed. The heat transfer coil 18 of FIG. 2a is shown with a plastic coating 30. As previously mentioned, coating 30 is preferably polymethylmethacrylate which has been dissolved in acetone and applied to coils 18 prior to placing the coils in the converter. When the converter has been assembled and the curing of porous silica-lime filler 16 is essentially completed, the curing temperature is raised to a temperature sufficient for complete gasification of the plastic coating, about 315 C. for polymethylmethacrylate. The gasified plastic coating may then be removed by evacuation, purging or both, leaving vapor passage 31 as shown in FIG. 2b. In operation acetylene vapor generated from within the interstices of silica-lime filler 16 will proceed to the passageways, illustrated by 31, surrounding heat transfer coil 13.

Referring to FIG. 3 there is illustrated the association of heat transfer coil 18 with screening material 22. The passageways 33 surrounding screen 22 are formed in a manner similar to the formation of passageways 31 sur rounding heat transfer coils 18. The acetylene flowing in passageways 31 joins the acetylene flowing in passageways 33. The combined acetylene flows proceed up passageway 33 and are ultimately discharged from the converter through the acetylene inlet-discharge connection.

Passageway 33 is, however, much larger than passageway 31. As previously stated passageway 33 is prepared in a similar manner to the method used for the preparation of passageway 31. We have found that the screen support material 22 must be sufficiently coated with the preferred gasifiable plastic, polymethylmethacrylate, to achieve a passage width of about 40 to 60 mils. It is necessary when one considers that all of the acetylene which is vaporized around a given heat transfer coil 18 proceeds along passageways 31 to passageway 33. If this larger flow passage 33 were not available, the velocity of the vaporized acetylene would markedly increase in passageway 33. If this occurred, the danger of entraining liquid acetylene in the gaseous acetylene flowing in passageway 33 would also increase. Such a situation would be inconsistent with the objectives of this invention. It should also be pointed out, however, that the width of passageways 31 and 33 should never exceed 7 inch.

Referring now to FIG. 4 there is illustrated the details of the flash arrester means housed within acetylene inletdischarge connection 24. The connection 24 is attached to inner vessel 19 and enclosed at its outer end by an adapter 40. A steel Wool pad 34 is placed within connection 24 and the remaining volume within adapter 40 is filled with a heat-stable particulate material 38 of suitable particle size to stabilize the acetylene therein e.g. inch diameter or smaller. An example of a suitable particulate material would be SAE 390 nickel shot. The metal wool pad 34 acts as a filter to exclude any particles of the porous silica-lime filler 16 from the bed of particulate material. More important, however, the metal pad 34 provides a resilient packing to maintain the particulate material tight within connection 24. This assembly acts as a flash arrester to quench any acetylene decomposition accurring at this point.

Returning to FIG. 1, preferred processes for charging and discharging the converter of this invention will be discussed. The schematic diagram located to the left of FIG. 1 illustrates an exemplary refrigerating system for use in charging acetylene to the converter. The schematic diagram to the right of FIG. 1 illustrates an exemplary heating system for use in discharging acetylene from the converter of this invention.

In charging the acetylene converter of this invention a liquid refrigerant, preferably ethylene, is withdrawn from tank 42 through conduit 43 and pumped by means of liquid pump 44 to conduit 46 having valve 47 therein. Ethylene is a preferred heat transfer fluid serving as a refrigerant for filling the converter and as a warming medium for withdrawal. The use of ethylene has at least two important advantages over heat transfer fluids such as acetone. First, its boiling point is low enough so that it can transfer heat by phase change either to or from liquid acetylene. Thus, ethylene can be boiled in heat transfer coils 18 to condense acetylene, or be condensed in heat transfer coils 18 at higher pressure to vaporize acetylene. Acetone boils at 56 C. and could not be vaporized against liquefying acetylene in the filling operation. Furthermore, acetone vapor cannot be condensed in the coils to withdraw acetylene unless a source of heat higher than ambient temperature is provided to boil the acetone. The second advantage of ethylene is its vapor pressure range corresponding to temperatures occurring in the converter. The ethylene pressure is always well above the acetylene pressure at equal temperatures; in the event of leakage in the heat transfer coil system acetylene would not enter the heat transfer coils. Other suitable heat transfer fluids which may be utilized in lieu of ethylene are monochlorodifiuoromethane ethane and nitrous oxide.

The ethylene, as a refrigerant fluid, enters manifold 21 at a minimum pressure of about 38 p.s.i.g. and a temperature of about 110 F. and is distributed to the plurality of heat transfer coils 18 embedded in porous silicalime filler 16. Simultaneously, acetylene at approximate ly 50 p.s.i.g. and ambient temperature is introduced into the vessel 10 of the acetylene converter through conduit 31, passes through flash arrester means 28 and enters inner vessel 19 through acetylene inlet-discharge connections 24. When the acetylene is at 50 p.s.i.g. the ethylene is preferably at about 60 p.s.i.g. and F. The compressed acetylene flows down passageways 33 and 31 enters the interstices of porous silica-lime filler 16 and condenses therein. Liquid ethylene boiling in heat transfer coil 18 removes the heat of condensation of the acetylene.

Vaporous ethylene flows up through heat transfer coils 18 to manifold means 29 and is withdrawn from inner vessel 10 through conduit 50 having valve 52 therein. The Vaporous ethylene is passed to heat exchange path 58 in heat exchanger 54 wherein the Vaporous ethylene is cooled and condensed against a suitable refrigerant flowing in heat exchange path 56. The condensed ethylone is then passed from heat exchanger 54 through conduit 60 to storage tank 42 for recirculation through heat transfer coils 18 of inner vessel 10.

Pump 44 is not essential to the operation of the ethylene warming system. By elevating tank 42 and condenser 58 to an appropriate height, the liquid pressure needed for circulation can be provided by gravity.

When the converter is filled to a predetermined weight of acetylene, the admission of gaseous acetylene is discontinued and ethylene refrigerant is still passed to the converter for a short time to reduce the acetylene pressure therein to say about 5 p.s.i.g. Continued circulation of ethylene with ethylene pressures below 38 p.s.i.g. will soon produce solid acetylene, and additional refrigeration is thus stored advantageously in the system by the further phase change. However, if the stored refrigeration is not needed, it is preferable to avoid the solid phase and minimize heat requirements during withdrawal by discontinuing ethylene circulation at 38 p.s.i.g. or above. A measured quantity of ethylene, suflicient to operate the warming circuit, is then sealed in coils 18 within the converter by closing valves 47 and 52 and is confined to within the insulated cold zone by means of a suitable liquid trap (not shown) in conduit 46 immediately below manifold 21. The filled converter is then disconnected from the refrigerating system and is transported to the consumer where conduit 31 is connected to a consuming means (not illustrated). The ethylene transported with the converter now acts as an efficient heating medium by virtue of a higher pressure maintained on the ethylene system suflicient to condense rather than boil ethylene in heat exchange with liquid acetylene. Furthermore, while the acetylene was condensed at 50 p.s.i.g. during filling it is withdrawn at a lower pressure, for example, 20 p.s.i.g.

When the acetylene is ready to be withdrawn from the converter, valve 47 is opened and the liquid ethylene is drained from the heat transfer coils 18 through conduit 62 and passed to heat exchange path 66 in boiler 64 wherein the liquid ethylene is boiled against a suitable source of heat such as heating fluid flowing in heat exchange path 67. The vaporized ethylene leaving heat exchange path 66 is passed to conduit 50 through conduit 68, then it enters manifold means 20 for distribution to heat transfer coils 18. The Vaporous ethylene arenas? condenses in coils 18 and the resulting condensate is passed out of the converter through conduits 46 and 62. for Warming and recirculation as described above.

At 70 p.s.i.g. ethylene boils and condenses at about -8S F. thus providing a suitable temperature difference within the converter for boiling acetylene whose corre sponding temperature is about 90 F. The temperature of the discharging operation is sufiiciently low enough to employ an atmospheric vaporizer as boiler 64. The rate of heat introduction to the converter from the ethylene heating system is controlled by the pressure within the converter. The pressure within the converter is sensed through instrument line '72 which passes a suitable signal to control valve 70 which regulates the amount of ethylene passed to heat transfer coils 1S. Ir" the rate of acetylene Withdrawal reduces the converter pressure below a predetermined level valve 7% will be caused toopen and will allow additional ethylene to enter coils 18 for condensation therein. This results in increased acetylene vaporization within the porous silica-lime filler which in turn restores the converter pressure. It is preferable to situate boiler 6 below heat transfer coils 18 so that a hydrostatic head may be maintained between the liquid ethylene levels in coils 18 and boiler 64. This hydrostatic head is maintained by valve 79 and provides the driving force for circulation of the ethylene fluid during the discharging process.

While there are no rapid or abrupt pressure fluctuations in the ethylene system, there is nevertheless a progressive increase in the ethylene system pressure as the amount of liquid acetylene in the converter is reduced. This is caused by the gradual depletion of the cold liquid acetylene within the porous silica-lime filler 16, which tends to decrease the rate of heat transfer to the liquid acetylene. To maintain the acetylene withdrawal rate, the ethylene system temperature (and pressure) will increase to provide the needed heat transfer to the liquid acetylene. The ethylene system pressure at the beginning of withdrawal of acetylene from the converter may be about 60 p.s.i.g. This pressure will steadily increase as acetylene is withdrawn from the converter and may rise as high as 750 p.s.i.g.

The repeated making and breaking of connections in the use of a closed ethylene system will not introduce air into the system provided that low-volume, self-sealing quick connectors are used. The small unavoidable ethylene leakage which occurs each time such connections are joined will effectively purge air from the connections.

What is claimed is:

1. A method for storing and dispensing acetylene which comprises charging gaseous acetylene to a porous solid filler mass and simultaneously cooling such mass by indirect heat exchange with a liquid refrigerant having a normal boiling point below about 70 C. thereby condensing the acetylene in the mass; storing the resulting condensed acetylene in the mass and simultaneously maintaining the liquid refrigerant-filler mass in indirect heat exchange; thereafter terminating said indirect heat eX- change; vaporizing said liquid refrigerant external to said mass; evaporating the condensed acetylene contained in the porous filler mass by indirectly heat exchanging the vaporized refrigerant with such mass thereby simultaneously condensing the refrigerant; and discharging the evaporated acetylene from said mass.

2. An acetylene converter comprising an inner vessel and an outer shell; thermal insulating material disposed between said inner vessel and said outer shell; a porous silica-lime filler within said inner vessel; at least one acetylene inlet-discharge connection adapted to said vessel to convey and withdraw gaseous acetylene therefrom; a plurality of heat transfer surfaces embedded within said porous silica-lime filler, and a system of passageways associated with said heat transfer surfaces in direct corn munication with the inlet-discharge connection for receiving and discharging acetylene from the pores of said porous silica-lime filler; wherein the outer surface of said heat transfer surfaces comprise one Wall of a first group of said passageways and said porous silica-lime filler comprises another wall of such group; and wherein said porous silica-lime filler comprises the walls of a second group of passageways, such group interconnecting with the passageways of said first group and directly communicating with the inlet-discharge connection; manifold means located at the ends of said inner vessel, said manifold means being adapted to said heat transfer surfaces to convey and discharge therefrom. a heat transfer fluid.

3. An acetylene converter according to claim 2 wherein said heat transfer surfaces presenting at least about 1.0

A ft. of heat transfer area per cubic foot of porous silicalime filler.

4. An acetylene converter according to claim 2 wherein flash arrester means are provided in said acetylene inletdischarge connection.

5. An acetylene converter according to claim 2 wherein said second group of passageways enclose screening material, the size of such passageways being relatively larger than the size of said passageways in said first group.

6. An acetylene converter according to claim 4 wherein said flash arrester means comprises a steel wool pad; heat stable particulate material, said steel wool pad being positioned such that the particulate material is excluded from said porous silica-lime filler; and a packing of small tubes dividing said inlet-discharge connection into small passages.

References Cited in the file of this patent UNITED STATES PATENTS 661,401 Fouche Nov. 6, 1900- 1,230,531 Stephenson June 19, 1917 1,799,803 Miller Apr. 7, 1931 1,863,958 Wolff et a1 June 21, 1932 2,234,738 Maude Mar. 11, 1941 2,992,540 Grosse et a1 July 18, 1961 I FOREIGN PATENTS 123,538 Russia Mar. 11, 1959 628,988 Canada Oct. 10, 1961 

1. A METHOD FOR STORING AND DISPENSING ACETYLENE WHICH COMPRISES CHARGING GASEOUS ACETYLENE TO A POROUS SOLID FILLER MASS AND SIMULTANEOUSLY COOLING SUCH MASS BY INDIRECT HEAT EXCHANGE WITH A LIQUID REFRIGERANT HAVING A NORMAL BOILING POINT BELOW ABOUT -70*C THEREBY CONDENSING THE ACETYLENE IN THE MASS; STORING THE RESULTING CONDENSED ACETYLENE IN THE MASS AND SIMULTANEOUSLY MAINTAINING THE LIQUID REFRIGERANT-FILLER MASS IN INDIRECT HEAT EXCHANGE; THEREAFTER TERMINATING AID INDIRECT HEAT EXCHANGE; VAPORIZING SAID LIQUID REFRIGERANT EXTERNAL TO SAID MASS; EVAPORATING THE CONDENSED ACETYLENE CONTAINED IN THE POROUS FILLER MASS BY INDIRECTLY HEAT EXCHANGING THE VAPORIZED REFRIGERANT WITH SUCH MASS THEREBY SIMULTANE- 